@Configuration
public class DataSourceConfig {
    @Bean(name = "primaryDataSource")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        return DataSourceBuilder.create().build();
    }
}

spring:
  datasource:
    primary:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/test1
      username: root
      password: root
    secondary:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/test2
      username: root
      password: root

@Repository
public class UserRepository {
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;
    @Autowired
    @Qualifier("secondaryDataSource")
    private DataSource secondaryDataSource;
    public List<User> getUsersFromPrimary() {
        JdbcTemplate jdbcTemplate = new JdbcTemplate(primaryDataSource);
        List<User> users = jdbcTemplate.query("SELECT * FROM users", new BeanPropertyRowMapper(User.class));
        return users;
    }
    public List<User> getUsersFromSecondary() {
        JdbcTemplate jdbcTemplate = new JdbcTemplate(secondaryDataSource);
        List<User> users = jdbcTemplate.query("SELECT * FROM users", new BeanPropertyRowMapper(User.class));
        return users;
    }
}

@Configuration
public class DataSourceConfig {
    @Value("${spring.datasource.type}")
    private Class<? extends DataSource> dataSourceType;
    @Bean(name = "masterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().type(dataSourceType).build();
    }
    @Bean(name = "slaveDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource() {
        return DataSourceBuilder.create().type(dataSourceType).build();
    }
    @Bean(name = "dynamicDataSource")
    public DataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DataSourceType.MASTER.name(), masterDataSource());
        targetDataSources.put(DataSourceType.SLAVE.name(), slaveDataSource());
        dynamicDataSource.setTargetDataSources(targetDataSources);
        dynamicDataSource.setDefaultTargetDataSource(masterDataSource());
        return dynamicDataSource;
    }
}

public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        return DynamicDataSourceContextHolder.getDataSourceType();
    }
}

public class DynamicDataSourceContextHolder {
    private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();
    public static void setDataSourceType(String dataSourceType) {
        contextHolder.set(dataSourceType);
    }
    public static String getDataSourceType() {
        return contextHolder.get();
    }
    public static void clearDataSourceType() {
        contextHolder.remove();
    }
}

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dynamicDataSource"/>
    <property name="typeAliasesPackage" value="com.example.model"/>
</bean>

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DataSource {
    DataSourceType value() default DataSourceType.MASTER;
}
@Aspect
@Component
public class DynamicDataSourceAspect {
    @Pointcut("@annotation(com.example.annotation.DataSource)")
    public void dataSourcePointcut() {
    }
    @Before("dataSourcePointcut()")
    public void before(JoinPoint joinPoint) {
        DataSource dataSource = getDataSource(joinPoint);
        if (dataSource != null) {
            DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name());
        }
    }
    @After("dataSourcePointcut()")
    public void after(JoinPoint joinPoint) {
        DynamicDataSourceContextHolder.clearDataSourceType();
    }
    private DataSource getDataSource(JoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        if (method.isAnnotationPresent(DataSource.class)) {
            return method.getAnnotation(DataSource.class);
        }
        return null;
    }
}